Though love themes mostly deal with the phase of attraction and relationship between two young hearts and the familiar yet tiring battle through prejudice and family opposition, each is driven by a different daemon. Kaadhalil Vizhunden deals with an intense love affair and also discusses the hero's perspective towards the whole issue.

Sabha (Naghulan) has had a tough and troubled childhood. His experience in dealing with his drunkard father and all the related torturous episodes make him feel alone and deprived of true love. Moreover, his rough life also causes a dent in his psyche and inculcates a feeling of insecurity and self-doubt. Propelled by these negative tendencies, sensitive Sabha thrives on daydreaming and pushes through life more on doubt than on certitude. An accomplished basketball player, the frequent matches give him welcome breaks from his habitual brooding and they are his only source of entertainment.

Meera (Sunena) enters his life like a whiff of fresh air. With her around, Sabha recognizes a positive energy and support. After an accident which lands him in hospital for a few days, Sabha also gets a chance to witness Meera's humanitarian side. Attracted by the fascinating aspects of her personality, Sabha falls in love with Meera and hopes that she will fill the void in his life.

Meanwhile, Meera too develops a liking towards Sabha. Except a nagging uncle (Hariraj) who is forever bent upon grabbing her massive assets, she too has no family connections to fall back on. Sabha's unassuming personality charms her. When both of them warm up to the affair, Sabha leaves town to play a crucial match. When he comes back, Meera is dead.

The news comes as a shock to the young man. Moreover, the mind-boggling speed at which things took place in his absence makes it impossible for him to assimilate its full magnitude. Dazed and driven by a maelstrom of confusion and loss, Sabha kidnaps his lover's dead body and preserves it in his abode. Subsequently, Inspector (Sampath) and Meera's uncle chase Sabha and ask him to surrender. Unruffled by the commotion around him, Sabha settles into a delusion that his lover is still alive and sets up a routine with the corpse. Eventually he discovers the truth behind Meera's sudden death. What is the truth? What does he decide to do now? How does he extract his revenge? Kaadhalil Vizhunden's climax reveals everything!

Kollywood audiences have seen so many movies with a psychological twist. But debutante director Prasath has offered his film with a touching mood. The film's dialogues and its sequences progress at a very realistic pace and wrap the audiences with a natural charm. Vijay Antony's music has already become a raging sensation among the country's youth. The 'Nakka Mukka' song is on virtually everyone's lips. Vijay Milton's camera adds a youthful touch. Boys' hero Naghulan's involvement in Kaadhalil Vizhunden is pretty evident. The tremendous physical makeover is the first and foremost proof; from the chubby immature adolescent in Boys to a fit, handsome and sensible young man in Kaadhalil Vizhunden, the fledgling hero makes a strong impression. Apparently, Naghulan has also made the transition felt in terms of his performance. Heroine Sunena too has matched her performance with that of Naghulan. Kaadhalil Vizhunden is the maiden film production venture of Sun Pictures, a well-known broadcasting media conglomerate. Incidentally, their first step has also turned out to be a huge success.